Equine body temperature and progesterone fluctuations during estrus and near parturition.

The research conducted attempts to understand if mare’s body temperature and blood progesterone level can predict their estrus period, ovulation and parturition. The study confirms that there’s no correlation between rectal temperature and progesterone concentration or the environmental temperature, and these parameters cannot be used to predict estrus, ovulation, and parturition in mares. However, the changes in serum progesterone levels can assist in detecting estrus.

Objective of the Research

• The main goal of the research was to identify if changes in body temperature and progesterone concentration could predict critical reproductive events (estrus, ovulation, and parturition) in mares.

Methods & Procedures

• Body temperature and serum progesterone levels were measured in mares across multiple points in time.
• These measurements were examined with respect to different stages of the estrous cycle and the stage of pregnancy.
• Statistical analyses were conducted to assess correlations between these factors and the variables of interest (estrus, ovulation and parturition).

Findings

• The study found no significant correlation (P > 0.1) between rectal temperature and environmental temperature or progesterone concentration.
• Similarly, there was no identifiable pattern or change in body temperature that could indicate or predict estrus, ovulation or the onset of parturition.
• However, the progesterone concentration did correlate with the stage of the estrous cycle and the stage of pregnancy, implying that changes in progesterone levels can indeed indicate estrus.
• These substantial changes in serum progesterone concentration are noteworthy during the estrus period, but they were not of predictive value for ovulation or parturition.

Conclusions

• Although progesterone concentration changes relative to the stage of estrous cycle and the stage of pregnancy, it could only assist in detecting estrus and not for predicting ovulation or parturition.
• Meanwhile, the body temperature (rectal temperature) showed variations at different points in the day but, it could not be used for predicting essential reproductive events.